SECTION 3 - CHARACTERISTICS
3.1General
This section describes operating instructions and operational characteristics of the SM-2 Automatic Crew-Overboard Light. The information presented is in conformance with U.S. Coast Guard Specification 46 CFR 161.010 and 161.110.
The SM-2 is a lightweight, compact, battery operated, portable unit which uses modular construction for basic circuits to simplify maintenance and replacement procedures.
The SM-2 has been designed and tested to pass the tough ANSI/UL 1196 and MSC.81(70) requirements.
3.2Purpose
This unit is a portable electronic floating strobe light which automatically rights itself and begins flashing when dropped into water. The SM-2 is designed to be carried aboard all vessels, as well as artificial islands and fixed structures. It is to be used as part of the required survival equipment complement. The light is used to mark a position in the water, particularly in a crew-overboard situation. It must be installed and used in conjunction with other equipment as required by U.S. Coast Guard Regulations.
3.3Component Ratings
Circuit design and component selection is such that component ratings cannot be exceeded when the unit is operated throughout the entire range of all environmental tests. The SM-2 uses circuit components and construction techniques, which have been manufactured to the specifications and requirements of various civilian and Governmental agencies.
3.4Operation
Instructions for operation and maintenance of the SM-2 are given on the instruction plate (see Figure 3). This unit does not possess any exterior operating controls. The circuit is electronically activated by a gravity switch when the unit is inverted.
3.5Construction
The SM-2 consists of a case with a battery, switch, electric circuit, flashlamp, globe, lanyard attachment flange, mounting bracket, and a buoyant, non-absorbent unicellular polyfoam, used as filler material. The case is made of high-impact plastic, International Orange in color, which is constructed to receive all components necessary to produce the required light output. No additional signaling devices are incorporated in the unit. The lens is designed to withstand all impact tests that are required in this application. The watertight integrity of the equipment is assured by O-Ring seals between surfaces. The unit's ability to withstand any anticipated external forces is assured by the combination of material strength and assembly methods. Ballast consists of a metallic weight permanently secured in the bottom of the case. The case and related compounds do not flow at temperatures below +85°C or crack at temperatures down to -34°C.
3.6Lanyard
The size, weight, and shape of the light are suitable for conveniently throwing overboard while attached to a life ring buoy by means of a lanyard. A hole is provided in the bottom flange of the case for lanyard attachment.
3.7Mounting Bracket
The mounting bracket is designed to hold the light in the inverted position and prevent free movement of the light when properly secured within the bracket. The bracket is made of a corrosion-resistant plastic and is arranged for mounting on a vertical surface.
3.8Dimensional Stability
The SM-2 is capable of undergoing specified temperature humidity cycles with no signs of shrinkage or distortion which might impair its serviceability or watertightness.
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